Collision switch



July 12, mm. W. M. sMrrH COLLISION SWITCH Filed Dec. 51

I11 rel/tor Patented July 12, 1949 UNITED STATES PATENT OFFICE COLLISIONSWITCH Walter M. Smith, San Diego, Calif.

Application December 31, 1946, Serial No. 719,576

(Cl. ZOO-52) 1 Claim.

This invention relates to improvements in electric switches for shuttingoff the motive power of a motor vehicle in case the latter collides withan object or another vehicle.

The primary object of the invention is to provide means for reducing thefire hazard resulting from the participation in a collision of a motorvehicle driven by an internal combustion engine which uses highlyvolatile or explosive fuels. The invention will also prevent ordiscourage hit and run driving after collisions.

Specifically, the invention contemplates provision of a safety switchadapted to automatically break the ignition circuit of the motor vehicleengine upon the occurrence of a collision, the switch being extremelysimple in construction and highly efiicient in operation.

The exact nature of the present invention will become apparent from thefollowing description and considered in connection with the accompanyingdrawing, in which:

Figure 1 is a bottom plan view of a collision switch constructed inaccordance with the present invention.

Figure 2 is a central vertical sectional view of the switch shown inFigure 1, taken on the plane of line 22 of Figure 1.

Figure 3 is a horizontal section taken on line 3--3 of Figure 2.

Referring in detail to the drawing, the present switch includes aclosure cap 5 having a lateral horizontal flange 6 which is apertured asat 1 to facilitate bolting of the switch to a motor vehicle. An invertedcup-shaped casing 8 has its lower end removably screwed or secured inthe closure cap 5, and a central binding post 9 is fixedly secured toand extends through the top wall of casing 8. This binding post includesa screw Ill which extends through an aperture in the top wall of casing8 and is drawn tight by a nut ll threaded thereon. A second nut I2 isthreaded on the bolt I and coacts with the nut H for securing theterminal connection l3 of a conductor wire M to the binding post. Asecond central binding post I is fixedly secured to and extends throughthe closure cap 5, and this binding post I5 includes a bolt l6 passedthrough an aperture of the cap 5 and having an inner contact head i!formed at the top with a concave seat [8. A nut I9 is threaded on thebolt [6 to draw the same tight, and a. second nut 20 is threaded on saidbolt l6 and coacts with the nut 19 to secure the terminal connection 2|of a second conductor 22 to said binding post I5. In practice, the wire22 is connected to a terminal of the vehicle battery, and

the wire I4 is connected to the ignition coil so that the present switchis interposed or installed between the battery and the coil.

A solid metallic conducting ball 23 is arranged in the casing 8 and isadapted to rest in the seat M. A helical contact spring 24 is arrangedin the casing 8 and is attached at its upper end to the binding post 9so that the lower end of said spring is arranged to bear upon the ball23 and thereby yieldingly hold the latter in the seat It. In this way,an electrical connection is normally provided between the binding posts9 and I5 so as to close the ignition circuit until the ball 23 is jarredfrom between the contact head I! and the contact spring 24 by violentimpact of the vehicle with an object or another vehicle. As soon as thelatter occurs, the electrical connection between the binding posts 9 andi5 is broken so that the ignition circuit of the vehicle engine isopened for throwing the engine out of operation. As shown, a splitwasher 25 is placed on the bolt it within casing 8 and on the head ofsaid bolt, and the upper end of spring 24 is extended through and abovethe washer 25 so that when the nut l i is tightened, the upper end ofthe spring 24 is securely attached to the binding post 9.

The present switch may be mounted on the vehicle so that it is diiiicultof access, thereby delaying resetting of the switch following acollision, which resetting requires removal of the casing 8 from the cap5 and replacement of the ball 23 in the seat l8, as well as replacementof the casing 8 with respect to the cap 5. It will be apparent that thepresent switch prevents the electric current of the ignition system ofthe vehicle engine from igniting fuel which may splash or leak as aresult of the collision.

The present switch is extremely simple in construction, economical tomanufacture, and easy to install and use.

What I claim is:

A collision switch including a bottom closure cap having means tofacilitate attachment thereof to a motor vehicle, an inverted cup-shapedcasing having its lower end removably secured in said closure cap, acentral binding post fixedly secured to and extending through the topwall of said casing, a second central binding post fixedly secured toand extending through the closure cap and having an inner contact headformed at the top with a concave seat, a conducting ball adapted to restin said seat, and a helical contact spring in the casing attached at itsupper end to the first named binding post and adapted to bear at itslower end upon said ball to yieldingly hold the latter in said seat andthereby provide an electrical connection between said binding postsuntil the ball is jarred from between the contact head and the contactspring by violent impact of the vehicle with an object or anothervehicle, said conducting ball being of a diameter to pass into the spacein the casing about the contact head of the second binding post and torest on the closure cap entirely below the contact spring.

WALTER M. SMITH.

REFERENCES CITED The following references are of record in the file ofthis patent:

Number Number 4 UNITED STATES PATENTS Name Date Cole et al Sept. 13,1932 Tucker et a1 Oct. 6, 1936 Williams et a1 Dec. 26, 1939 Brooks Nov.18, 1941 FOREIGN PATENTS Country Date France Nov. 22, 1935

